feat(poc): rewind MCP, skill, and recover-ladder docs

Initial PoC: find_protection, tagged checkpoints, FLR, mutating catalog.
Lab 10.9 status enums (0=Initializing, 1=MeetingSLA). Credentials stay in gitignored config.json.

src/zerto_rewind_mcp/catalog.py

@@ -0,0 +1,73 @@
+"""Mutating catalog: opt-in list of tools that must be guarded."""
+
+from __future__ import annotations
+
+import json
+from dataclasses import asdict, dataclass
+from pathlib import Path
+from typing import Any
+
+
+@dataclass
+class CatalogEntry:
+    server: str
+    tool: str
+    vm_arg: str
+    notes: str = ""
+
+    def key(self) -> tuple[str, str]:
+        return (self.server.lower(), self.tool.lower())
+
+    def as_dict(self) -> dict[str, str]:
+        return asdict(self)
+
+
+def entry_from_dict(raw: dict[str, Any]) -> CatalogEntry:
+    server = str(raw.get("server") or "").strip()
+    tool = str(raw.get("tool") or "").strip()
+    vm_arg = str(raw.get("vm_arg") or "").strip()
+    if not server or not tool or not vm_arg:
+        raise ValueError("catalog entry needs server, tool, and vm_arg")
+    return CatalogEntry(
+        server=server,
+        tool=tool,
+        vm_arg=vm_arg,
+        notes=str(raw.get("notes") or ""),
+    )
+
+
+class MutatingCatalog:
+    def __init__(self, entries: list[CatalogEntry] | None = None, path: Path | None = None):
+        self._entries: dict[tuple[str, str], CatalogEntry] = {}
+        self.path = path
+        for entry in entries or []:
+            self._entries[entry.key()] = entry
+
+    def list(self) -> list[CatalogEntry]:
+        return sorted(self._entries.values(), key=lambda e: e.key())
+
+    def get(self, server: str, tool: str) -> CatalogEntry | None:
+        return self._entries.get((server.lower(), tool.lower()))
+
+    def add(self, entry: CatalogEntry) -> CatalogEntry:
+        self._entries[entry.key()] = entry
+        self.save()
+        return entry
+
+    def save(self) -> None:
+        if self.path is None:
+            return
+        payload = {"mutating_tools": [e.as_dict() for e in self.list()]}
+        self.path.parent.mkdir(parents=True, exist_ok=True)
+        if self.path.suffix == ".json" and self.path.exists():
+            existing = json.loads(self.path.read_text(encoding="utf-8"))
+            if isinstance(existing, dict):
+                existing["mutating_tools"] = payload["mutating_tools"]
+                payload = existing
+        self.path.write_text(json.dumps(payload, indent=2) + "\n", encoding="utf-8")
+
+    @classmethod
+    def from_config(cls, data: dict[str, Any], path: Path | None = None) -> MutatingCatalog:
+        raw = data.get("mutating_tools") or []
+        entries = [entry_from_dict(item) for item in raw]
+        return cls(entries, path=path)